pond under raised duck house?

First time duck keepers here. We're going to raise 4 Welsh Harlequin ducks outdoors. I was planning to build a raised coop, not unlike the henhouse of "the Garden Coop" plan. Then considering having a 4' kiddie pool halfway under the house and halfway under the ramp in front of the house. That way it should still get plenty of light but part of it would be shaded. This would make very good use of the space I have available and the pool could be easily maintained from a gate in the back.

Is this plan a bad idea for any reason?

Also, I found reference that ducks do not need nesting boxes. Is this the case? Their house is empty except for bedding?

It's my understanding most duck breeds do not use nesting boxes. Just keep PLENTY of bedding material, a good depth, for them to make their own nests in it. You may find that many ducks simply lay their eggs wherever they wander, too....

And I echo the recommendation to have a way to easily drain the duck pond. I think it's a cool idea to put it UNDER the duck house, even partially, but you have GOT to have a way to drain it for cleaning on a fairly frequent basis.

Keep in mind it will be HEAVY even when partially filled with water. Also, you want to be able to hose it down to really clean it out. You'll probably want the house at least three feet off the ground to better manuever the pool back and forth and rinse/fill it. I've had ducks for 7 years now and am still trying to find the "perfect" pool set up